The present invention is directed to a device for controlling the flow of liquid through two or more flexible tubes. The present invention finds particular application in the field of blood donation and in the tubing sets or fluid circuits used for such donations.
A disposable plastic tubing set or fluid circuit is typically used for collecting blood from a donor. The disposable tubing set includes a venipuncture needle for insertion into the arm of the donor. The needle is attached to one end of a flexible plastic tube which provides a flow path for the blood. The other end of the plastic tube is attached to one or more plastic bags or containers for collecting the withdrawn blood.
The blood tubing set may also include a sampling sub-unit. The sampling sub-unit allows for collection of a sample of blood, which sample can be used for testing of the blood. Preferably, the sample is obtained prior to the xe2x80x9cmainxe2x80x9d collection of blood. Collecting the sample prior to the main collection reduces the risk that bacteria residing on the donor""s skin where the needle is inserted (i.e., in particular, the small section of detached skin commonly referred to as the xe2x80x9cskin plugxe2x80x9d) will not enter the collection container and contaminate the blood collected for transfusion. Thus, it is preferred that the blood sample, which may include the skin plug, be diverted from the main collection container.
An example of a blood tubing set with such a xe2x80x9cpre-donationxe2x80x9d sampling sub-unit is described in U.S. patent application Ser. No. 09/364,628 filed Jul. 29, 1999 and U.S. patent application Ser. No. 09/492,060 filed Jan. 27, 2000, which are incorporated by reference herein. The tubing sets described therein include a needle and a length of tubing, one end of which is attached to the needle and the other end of which is attached to one or more collection containers. The tubing set also includes an additional line which is branched from the main line at a Y-connection site in the tubing set. The branched line is attached to a sampling pouch for collecting a selected volume of blood from which samples may be obtained.
The tubing set described above also includes multiple and separate flow control devices for controlling the flow of biological fluid (e.g., blood) through the tubing set and to the sampling pouch and/or collection container. Flow control devices commonly used are the Roberts-type clamps, which are well known in the art. The Roberts-type clamps are placed on the tubing line leading to the blood collection container and on the tubing line leading to the sampling pouch. A Roberts-type clamp generally comprises a single strip of plastic where the ends of the strip are curved toward each other to engage each other in a snap-fit, spring relation. The body of the clamp includes a pair of apertures through which the tubing passes. The clamp further includes a pair of projections which compress the tubing when the body of the clamp is depressed, thereby restricting flow through the tube. Clamps of this type are generally described in U.S. Pat. Nos. 3,942,228 and 6,089,527, both of which are incorporated herein by reference.
By selectively opening and closing the different flow paths (by depressing or releasing the clamps), the technician can control the flow of blood from the donor, diverting the blood to the desired container or sampling pouch, as necessary. For example, in a pre-donation sampling, the flow path leading to the collection container may be initially compressed and closed, while the flow path leading to the sampling pouch remains open. Once a sufficient volume of blood has been collected in the sampling pouch, the flow path leading to the sampling pouch may be closed and the flow path leading to the collection container may then be opened. As noted above, a xe2x80x9cpre-donationxe2x80x9d sampling prevents the skin plug from entering the collection container and instead, diverts it to the sampling pouch, where blood that will not be transfused to a patient is collected.
Another example of a fluid circuit or tubing set with a sampling unit is described in International Application No. WO 00/24313. That publication describes a tubing set which also allows for diversion of a quantity of blood from a donor to a sampling sub-unit. The system includes a device that allows the technician to direct the blood or other biological fluid to either the blood collection container or to the sampling sub-unit. The device includes a housing that has an inlet and two or more outlet ports, with tubes connected to the inlet and outlet ports. By turning a knob on the flow control device, flow communication can be established between the inlet and one or the other of the outlet ports, as necessary. The flow control device described above overcomes the inconvenience of having to separately open and clamp off the different lines of the tubing set.
While the flow control devices described above have worked satisfactorily, further improvements in selectively controlling the flow of blood or other biological fluid through a tubing set are desired. For example, it would be desirable to provide a flow control device that is inexpensive and easy to manufacture, easily adaptable for use with two or more tubes, and easy to use by the technician.
In one aspect, the present invention is directed to a flow control device that includes a first clamp having a body with a first end and a second end. The ends of the first clamp are adapted for locking engagement with each other. The first clamp further includes at least two apertures in the body for receiving a flexible tube and a tubing contacting member for compressing a flexible tube. The flow control device also includes a second clamp in association with the first clamp. The second clamp, likewise, includes a body having first and second ends which are adapted for locking engagement with each other. The second clamp also includes at least two apertures for receiving a flexible tube and at least one tubing contacting member for compressing a tube. The second clamp further includes a releasing member for releasing the first clamp from the compressed position.
In another aspect, the present invention is directed to a flow control device having a body with a first and second end wherein the ends are adapted for locking engagement with each other. The flow control device includes at least two apertures in the body for receiving a flexible tube and at least one tubing contacting member for compressing a flexible tube. The flow control device also includes a connector for mating with a receiving member of another flow control device and a receiving member for mating with a connector of another flow control device.
In a further aspect, the present invention is directed to a flow control device that includes a body having a first end and a second end wherein the first end includes a notch and the second end includes a lip adapted for engagement with the notch. The second end further includes an extension that is laterally and axially spaced from the portion of the lip adapted for engagement with the notch.
In still another aspect, the present invention is directed to a flow control device that includes a first clamp and a second clamp adjacent to and in association with the first clamp. The first clamp includes a body having a first end and a second end, wherein the first end comprises a notch and the second end comprises a lip that is adapted for engagement with the notch. The first clamp includes at least two apertures in the body for receiving a flexible tube and at least one tubing contacting member for compressing a flexible tube. The second clamp, likewise, includes a body having a first end and a second end wherein the first end comprises a notch and the second end comprises a lip adapted for engagement with the notch. The lip of the second clamp further includes an extension that is adapted for contact with the first clamp end.